基于SrTiO3的频率可调谐太赫兹超材料吸波器(英文)

Frequency Tunable Terahertz Metamaterial Absorbers Based on SrTiO3

基于温度敏感材料钛酸锶(SrTiO3)提出了两款频率可调谐太赫兹(THz)超材料(MM)吸波器。由于SrTiO3材料的复值介电常数与外界温度相关,因此基于SrTiO3材料的太赫兹超材料吸波器的谐振频率可随外界温度变化。一款是基于十字金属谐振结构和SrTiO3介质层实现的,在200~400 K的温度范围内,其谐振频率可在1.62~2.44 THz的宽频带范围内实现主动调谐。另一款超材料吸波器通过在十字环金属谐振结构内填充SrTiO3材料来实现,而中间介电层仍然采用常见的聚二甲基硅氧烷(PDMS)材料。当外部温度从200 K变为400 K时,谐振频率从1.11 THz移至1.58 THz,频率偏移达到了470 GHz,实现了频率可调的太赫兹超材料吸波器。可调谐超材料吸波器的实现可进一步扩展超材料吸波器的应用领域,从而更好地适应如太赫兹成像、太赫兹检测、传感和隐身等各种应用。

Two types of frequency tunable metamaterial(MM)absorbers in the terahertz(THz)spectrum regime based on the temperature-sensitive material SrTiO3 were presented.The resonant frequencies of THz MM absorbers based on SrTiO3 can change with the external temperature as the complex permittivity of SrTiO3 is related to the external temperature.One was realized based on the cross-shaped metallic resonant structure and SrTiO3 middle dielectric layer.The resonant frequency can be actively tuned across a wide band of frequencies from1.62 THz to2.44 THz in the temperature range from200 K to 400 K.Another one was realized by filling SrTiO3 material inside the cross ring metallic resonant structure,while the middle dielectric layer still used the common polydimethylsiloxane(PDMS)material.The resonant frequency shift of the absorption peak reaches 470 GHz with the resonant frequency from1.11 THz to 1.58 THz when the external temperature changes from200 K to 400 K,thus the frequency tunable MM absorber was achieved.The realization of frequency tunable MM absorbers can further extend the application fields of the MM absorbers to better adapt to various applications,such as THz imaging,THz detection,sensing,stealth and solar cells.